原标题：Intersil ISL70001SEH 辐射加固FPGA电源解决方案

　　Intersil 公司的ISL70001SEH是集成了MOSFET的辐射和SEE加固的高效同步降压稳压器,输入电压3V到5.5V,输出电压从0.8V到输入电压的 ~85%,TJ ≤ +150℃时的输出负载电流6A,效率大于90%,开关频率1MHz或500kHz,辐射剂量为100 krad(Si),SEL和SEB LETTH 为86.4MeV/mg/cm2,主要用在FPGA, CPLD, DSP, CPU Core 和I/O电源,低压大容量分布电源.本文介绍了ISL70001SEH主要特性,方框图,主/从模式典型应用电路,以及辐射加固FPGA电源参考设计和 VIRTEX5MEZPWREV1Z 评估板框图,电路图,材料清单和PCB布局图.

　　Rad Hard and SEE Hard 6A Synchronous Buck Regulator ISL70001SEH

　　The ISL70001SEH is a radiation hardened and SEE hardened high efficiency monolithic synchronous buck regulator with integrated MOSFETs. This single chip power solution operates over an input voltage range of 3V to 5.5V and provides a tightly regulated output voltage that is externally adjustable from 0.8V to ~85% of the input voltage. Output load current capacity is 6A for TJ < +145℃.

　　High integration and class leading radiation tolerance makes the ISL70001SEH an ideal choice to power many of today’s small form factor applications. Two devices can be synchronized to provide a complete power solution for large scale digital ICs, like field programmable gate arrays (FPGAs), that require separate core and I/O voltages.

　　ISL70001SEH主要特性:

　　• ±1% Reference Voltage Over Line, Load, Temperature and Radiation

　　• Current Mode Control for Excellent Dynamic Response

　　• Full Mil-Temp Range Operation (TA = -55℃ to +125℃)

　　• High Efficiency > 90%

　　• Fixed 1MHz Operating Frequency

　　• Operates from 3V to 5.5V Supply

　　• Adjustable Output Voltage

　　- Two External Resistors Set VOUT from 0.8V to ~85% of VIN

　　• Bi-directional SYNC Pin Allows Two Devices to be Synchronized 180° Out-of-Phase

　　• Device Enable with Comparator Type Input

　　• Power-Good Output Voltage Monitor

　　• Adjustable Analog Soft-Start

　　• Input Undervoltage, Output Undervoltage and Output Overcurrent Protection

　　• Starts Into Pre-Biased Load

　　• Electrically Screened to DLA SMD 5962-09225

　　• QML Qualified per MIL-PRF-38535 Requirements

　　• Radiation Hardness

　　- Total Dose [50-300rad(Si)/s] . . . . . . . . . . .100krad(Si) min

　　- Total Dose [<10mrad(Si)/s] . . . . . . . . . . . . .50krad(Si) min

　　• SEE Hardness

　　- SEL and SEB LETeff . . . . . . . . . . . . 86.4MeV/mg/cm2 min

　　- SEFI X-section (LETeff = 86.4MeV/mg/cm2) 1.4 x 10-6 cm2 max

　　- SET LETeff (< 1 Pulse Perturbation) 86.4MeV/mg/cm2 min

　　ISL70001SEH应用:

　　• FPGA, CPLD, DSP, CPU Core or I/O Voltages

　　• Low-Voltage, High-Density Distributed Power Systems

　　图1.ISL70001SEH方框图

　　图2.ISL70001SEH典型应用框图

　　图3.ISL70001SEH 5V输入电压和主模式同步应用电路图

　　图4.ISL70001SEH 3.3V输入电压和从模式同步应用电路图

　　This application note discusses the VIRTEX5MEZPWREV1Zboard, Intersil’s reference design to power FPGA’s in a radiation hardened environment. This particular board is optimized to power a Xilinx’s Virtex-5 FPGA and features the ISL70001SRH and ISL70002SRH, rad hard POL buck regulators along with the ISL75051RH rad hard LDO.

　　The Virtex-5 requires a core voltage of 1.0V, which is supplied by the ISL70002SRH, an auxiliary voltage of 2.5V, which is supplied by the ISL70001SRH, and an I/O voltage of 3.3V which is supplied by the ISL75051RH.

　　图5.VIRTEX5MEZPWREV1Z 评估板框图

　　The ISL70001SRH and ISL70002SRH are both radiation hardened and SEE hardened high efficiency, monolithic synchronous buck regulators with integrated MOSFETs. These single chip power solutions operate over an input voltage range of 3V to 5.5V and provide a tightly regulated output voltage that is externally adjustable from 0.8V to ~85% of the input voltage. The ISL70001SRH can provide up to 6A (TJ ≤ +145°C) of output current while the ISL70002SRH can provide up to 12A (TJ ≤ +150°C) of output current.

　　The ISL75051SRH is a radiation hardened, low voltage, high current, single output LDO specified for up to 3.0A of continuous output current. It can operate over an input voltage range of 2.2V to 6.0V and is capable of providing output voltages of 0.8V to 5V with an external resistor divider. Dropout voltages as low as 65mV can be realized with this device.

　　图.辐射加固FPGA电源解决方案参考设计外形图

　　VIRTEX5MEZPWREV1Z评估板材料清单: